in fact 20mp is all that you will extract from D800 with less than perfect lens or with perfect lens but at ISO 800 upwards (give or take).

Not really sure how you come to that conclusion.

Did you really think you got 36mp resolution at every iso and with any lens?

Of course not, but I still would like to know how you arrived at the 20mp figure at ISO800.

...you mixed up our posts. The above is what ultimitsu wrote and the underlined is what I wrote.

In any case, most lenses (at least my lenses) outresolve the D800.

No they don't. In fact, it's doubtful that any lens outresolved the D800, so neither do yours. I have most of the pro glass between 14 and 200 mm.

Well, I think my lenses outresolve the D800.

It is an Internet hoax that you need new lenses with the D800.

It depends. Some of the new Zeiss lenses clearly exploit the full potential of the D800. Some Nikkor lenses most certainly need to be improved to match the D800 - most actually

Never the less, it is still an Internet hoax that you must buy new lenses if you buy the D800. It is certainly so that the same lens you have used before on any other FX performs better on the D800 than it performed on the "other" FX. Of course, the better your lens is the more you get out of the D800 high MP, but there is no need for new lenses just because one is buying the camera.